Google Cloud for Go

import "cloud.google.com/go"

Go packages for Google Cloud Platform services.

NOTE: These packages are under development, and may occasionally make backwards-incompatible changes.

NOTE: Github repo is a mirror of https://code.googlesource.com/gocloud.

News

September 8, 2016

• New clients for some of Google's Machine Learning APIs: Vision, Speech, and Natural Language.

• Preview version of a new Stackdriver Logging client in cloud.google.com/go/preview/logging. This client uses gRPC as its transport layer, and supports log reading, sinks and metrics. It will replace the current client at cloud.google.com/go/logging shortly.

Supported APIs

Google API	Status	Package
Datastore	beta	cloud.google.com/go/datastore
Storage	beta	cloud.google.com/go/storage
Pub/Sub	experimental	cloud.google.com/go/pubsub
Bigtable	beta	cloud.google.com/go/bigtable
BigQuery	experimental	cloud.google.com/go/bigquery
Logging	experimental	cloud.google.com/go/logging
Vision	experimental	cloud.google.com/go/vision
Language	experimental	cloud.google.com/go/language/apiv1beta1
Speech	experimental	cloud.google.com/go/speech/apiv1beta

Experimental status: the API is still being actively developed. As a result, it might change in backward-incompatible ways and is not recommended for production use.

Beta status: the API is largely complete, but still has outstanding features and bugs to be addressed. There may be minor backwards-incompatible changes where necessary.

Stable status: the API is mature and ready for production use. We will continue addressing bugs and feature requests.

Documentation and examples are available at https://godoc.org/cloud.google.com/go

Visit or join the google-api-go-announce group for updates on these packages.

Go Versions Supported

We support the two most recent major versions of Go. If Google App Engine uses an older version, we support that as well. You can see which versions are currently supported by looking at the lines following go: in .travis.yml.

Authorization

By default, each API will use Google Application Default Credentials for authorization credentials used in calling the API endpoints. This will allow your application to run in many environments without requiring explicit configuration.

Manually-configured authorization can be achieved using the golang.org/x/oauth2 package to create an oauth2.TokenSource. This token source can be passed to the NewClient function for the relevant API using a option.WithTokenSource option.

Google Cloud Datastore

Google Cloud Datastore (docs) is a fully- managed, schemaless database for storing non-relational data. Cloud Datastore automatically scales with your users and supports ACID transactions, high availability of reads and writes, strong consistency for reads and ancestor queries, and eventual consistency for all other queries.

Follow the activation instructions to use the Google Cloud Datastore API with your project.

First create a datastore.Client to use throughout your application:

client, err := datastore.NewClient(ctx, "my-project-id")
if err != nil {
	log.Fatalln(err)
}

Then use that client to interact with the API:

type Post struct {
	Title       string
	Body        string `datastore:",noindex"`
	PublishedAt time.Time
}
keys := []*datastore.Key{
	datastore.NewKey(ctx, "Post", "post1", 0, nil),
	datastore.NewKey(ctx, "Post", "post2", 0, nil),
}
posts := []*Post{
	{Title: "Post 1", Body: "...", PublishedAt: time.Now()},
	{Title: "Post 2", Body: "...", PublishedAt: time.Now()},
}
if _, err := client.PutMulti(ctx, keys, posts); err != nil {
	log.Fatal(err)
}

Google Cloud Storage

Google Cloud Storage (docs) allows you to store data on Google infrastructure with very high reliability, performance and availability, and can be used to distribute large data objects to users via direct download.

https://godoc.org/cloud.google.com/go/storage

First create a storage.Client to use throughout your application:

client, err := storage.NewClient(ctx)
if err != nil {
	log.Fatal(err)
}

// Read the object1 from bucket.
rc, err := client.Bucket("bucket").Object("object1").NewReader(ctx)
if err != nil {
	log.Fatal(err)
}
defer rc.Close()
body, err := ioutil.ReadAll(rc)
if err != nil {
	log.Fatal(err)
}

Google Cloud Pub/Sub

Google Cloud Pub/Sub (docs) allows you to connect your services with reliable, many-to-many, asynchronous messaging hosted on Google's infrastructure. Cloud Pub/Sub automatically scales as you need it and provides a foundation for building your own robust, global services.

First create a pubsub.Client to use throughout your application:

client, err := pubsub.NewClient(ctx, "project-id")
if err != nil {
	log.Fatal(err)
}

// Publish "hello world" on topic1.
topic := client.Topic("topic1")
msgIDs, err := topic.Publish(ctx, &pubsub.Message{
	Data: []byte("hello world"),
})
if err != nil {
	log.Fatal(err)
}

// Create an iterator to pull messages via subscription1.
it, err := client.Subscription("subscription1").Pull(ctx)
if err != nil {
	log.Println(err)
}
defer it.Stop()

// Consume N messages from the iterator.
for i := 0; i < N; i++ {
	msg, err := it.Next()
	if err == pubsub.Done {
		break
	}
	if err != nil {
		log.Fatalf("Failed to retrieve message: %v", err)
	}

	fmt.Printf("Message %d: %s\n", i, msg.Data)
	msg.Done(true) // Acknowledge that we've consumed the message.
}

Contributing

Contributions are welcome. Please, see the CONTRIBUTING document for details. We're using Gerrit for our code reviews. Please don't open pull requests against this repo, new pull requests will be automatically closed.

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms. See Contributor Code of Conduct for more information.